On Sensitivity Functions and Sensitivity Points – A Case Study for a DC-DC Buck Converter Model

Abstract

Several aspects regarding the ways the powerful concepts of sensitivity functions and sensitivity points can be used to analyze the robustness of a DC-DC converter model to component tolerances are presented. The first part of the paper comprises a discussion on the terminology for sensitivity points and their associated sensitivity functions. The rest of the paper presents how the above concepts can be used to describe time domain sensitivity of a converter with digital PID controller to the output filter parameters, with a special focus on the output voltage dynamics for load step scenarios. A distinct emphasis is devoted to semi-relative sensitivities which are shown to be simultaneously computed for all the parameters of interest and for any type of input signal.